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Datums for 8443725, Chelsea MA


NOTICE: All data values are relative to the MLLW.

Elevations on Mean Lower Low Water

Station: 8443725, Chelsea, MA
Status: Accepted (Oct 7 2003)
Units: Feet
Control Station: 8443970 Boston, MA
T.M.: 75
Epoch: 1983-2001
Datum: MLLW
DatumValueDescription
MHHW10.35Mean Higher-High Water
MHW9.90Mean High Water
MTL5.12Mean Tide Level
MSL5.24Mean Sea Level
DTL5.17Mean Diurnal Tide Level
MLW0.34Mean Low Water
MLLW0.00Mean Lower-Low Water
NAVD88
STND-13.72Station Datum
GT10.35Great Diurnal Range
MN9.56Mean Range of Tide
DHQ0.45Mean Diurnal High Water Inequality
DLQ0.34Mean Diurnal Low Water Inequality
HWI3.74Greenwich High Water Interval (in hours)
LWI9.93Greenwich Low Water Interval (in hours)
Max TideHighest Observed Tide
Max Tide Date & Time Highest Observed Tide Date & Time
Min TideLowest Observed Tide
Min Tide Date & Time Lowest Observed Tide Date & Time
HATHighest Astronomical Tide
HAT Date & Time HAT Date and Time
LATLowest Astronomical Tide
LAT Date & Time LAT Date and Time
Tidal Datum Analysis Periods
07/01/2002 - 09/30/2002




Products available at 8443725 Chelsea, MA

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services